Folding boat hull



1964 N. P. s. STRAUSSLER 3,116,496

FOLDING BOAT HULL Filed Sept. 28, 1961 2 Sheets-Sheet 1 22 20 FIG. 1.

17' FIG. 2.

IAIIENTOR:-

1964 N. P. s. STRAUSSLER FOLDING BOAT HULL 2 Sheets-Sheet 2 Filed Sept.28, 1961 FIG. 8. 2O 21 FIG. 10.

FIG.7. 13 W 12 FIG. 9.

United States Patent 3,116,496 FOLDING BOAT HULL Nicholas Peter SorrellStraussler, London, England,

assignor to F. A. Hughes & Co., Limited, London, England, a Eritishcompany Filed Sept. 28, 1961, Ser. No. 141,395 Claims priority,application Great Britain Oct. 3,1960 9 Claims. (Cl. 9-2) This inventionrelates to the construction of boats and more particularly to hulls ofthe kind that are commonly described as hard chine hulls in which theoverall crosssectional shape of the bottom panels are of a V-section atthe forward part of the hull gradually flattening out towards the aft ormid-portion of the hull to either a very fiat V-section or a horizontalline or even an inverted V-shape. The bottom panels are thus helicallytwisted in the longitudinal direction of the boat.

The object of the present invention is to provide a folding boat whosehull when unfolded has the features mentioned above and is automaticallyheld in open condition and resists collapse under transverse pressure. Afurther object is to connect the hull panels together in a manner whichfacilitates rapid unfolding of the hull of the boat ready for use.

According to the invention a folding boat hull comprising a first pairof flexible panels having contours identical to each other when the hullis folded and each having an upper convex edge, said panels beingconnected together along a continuous line including a keel portion anda bow and/or stern portion at adjacent identical lower edges by aflexible hinge, and a second pair of panels, said second panels beingconnected together along adjacent identical edges by a further flexiblehinge, further edges of said second pair of panels being connected tosaid first panels along said convex edges of the latter to which theyare identical in contour, said second panels when the boat is folded,lying between the first panels and within the area of the first panelsover the length of the latter,

The essential requirement of this invention is that all panels in theflat state have identical contours where they are joined to anotherpanel.

A construction-a1 form of the invention will now be described by way ofexample with reference to the accompanying drawings in to which:

FIGURE 1 is a side elevation of a boat hull, designed for a runabout,shown in the unfolded condition;

FIGURE 2, is a plan view of the hull shown in EEG- URE 1;

FIGURES 3 and 4 are front and rear views respectively of the unfoldedhull shown in FIGURE 1;

FEGURE 5 is a side elevation of the folded hull;

FIGURE 6 is a plan view of the folded hull as shown in FIGURE 5PlGUliE-S 7 and 8 are front and rear views respectively of the foldedhull shown in Figure 6;

FIGURE-S 9 and 10 are front and rear views of the hull in thesemi-unfolded condition, FIGURE 10 including arrows showing thedirection of movement of the panels during unfolding,

FIGURE 11 shows a cross-section through the flexible hinge whichconnects two panels of the hull together; and

FIGURE 12 shows a perspective view above and to the rear of the unfoldedhull having bracing members inserted therein together with seats andtransom.

From the drawings it is seen that the hull comprises a first pair offlexible panels l2, 13 forming the underside of the boat, said panelsbeing identical in contour when in the folded position and connectedtogether along Bilhfihb Patented Jan. 7, 1 354 identical edges by meansof a flexible hinge to be described hereafter. These edges comprise asubstantially straight keel portion 14 which extends over about twothirds to three quarters the length of the hull, and which is continuouswith a curved bow portion 15 being about one quarter to one third thelength of the hull.

Each panel I2, 13 comprises in the unfolded condition of the boat, aflat flexible sheet having a long approximately straight edge In and along slightly convex edge 17 extending over the length of the panel. Anend edge It; is formed at approximately right angles to the straightedge 16 and is about one sixth to one eighth the length of panel. Theedge 16 continues into a convex edge 19, forming the bow portion 15,which meets the convex edge 17. The edge in and the edge 19 extend overthe whole length of the panel.

The deck and sides are formed by a second pair of flexible panels 2%, Elwhich are identical in contour when in the folded position and connectedtogether along identical substantially straight or slightly curved edgesover the length of the deck portion by a flexible hinge 22.

Each panel 2t, 21 comprises in the unfolded condition of the boat, afiat flexible sheet having along convex edge 17' extending over thelength of the panel and a long concave edge 23 extending from one endover one sixth to one eighth the length of the panel. The edge 24 (FIG.5) is substantially straight or may be slightly curved to give an upwardcurve to the fore deck when the hull is unfolded. The edges 24!- extendupwardly and longitudinally to a position where the width of the hull is70 to percent of the maximum width. A fourth edge 25 is substantiallystraight and is in a plane at approximately right angles to the centrallongitudinal axis of the hull. Alternatively, this edge 25 may beinclined to the above-neutioned plane whereby the transom, referred tolater, may be outwardly or inwardly inclined.

The convex edge 17 of each deck and side panel is identical to the edgeI7 of the corresponding underside panel, these edges being connected toeach other by a flexible hinge similar to that forming the keel hinge.The panels 20, l are of such size that they fall within the areas of thepanels l2, l3 respectively.

FIGURES 5 to 8 show the hull in a folded position where the panels areflat against each other and substantially parallel to each other and bymoving the panels 12 and 13 apart as shown in FIGURES 9 and 1G in thedirection of the arrows (FIGURE 10 the panels 2% and 21 can then beflexed upwardly in the direction of the arrows (FIGURE 10). This actioncauses both deck and side panels and underneath panels to become flexedhelically.

in the unfolded condition the edges 16 and 19 lie on the centrallongitudinal axis of the hull. The aft or rear edge 18 of eachunderneath panel is substantially horizontal and the latter is twistedhelicnlly over its entire length.

The deck and side panels are also helically twisted over their entirelengths, the aft or rear edge 18 of each panel 21 being substantiallyvertical. The hinged together edges 2d lie in a vertical plane along thecentral horizontal axis of the hull. The most forward part of theforedeck portion of the panel lies in a plane which is inclined at anangle of from 5 to 20 degrees to the horizontal upwardly from the bowrearwards. It can, however, be horizontal or even inclined in the othersense.

The flexible hinge joining the panels together is shown in section inFIGURE 11. The hinge may be made of rubber or suitable synthetic plasticsuch as neoprene or polyvinylchloride and is an extruded or fabricatedstrip having a substantially U-shaped section. The two limbs 35 31 ofsaid strip are divided by recesses 32, 33 each having a width whosedimension is about equal to the thickness of the panel. re limbs aretapered at their outer edges to give a neat appearance. A concave groove34 is provided to reduce the thickness at the junction of the two limbsin order to make the strip effective as a hinge.

On assembly, the panels are placed in the recesses in the limbs whichare suitably treated with an adhesive.

The hull ready for use is completed as shown in FIGURE 12 by theaddition of a transom 36 which is attached to the aft end of the deckand side panels and underneath panels by suitable means (not shown) forexample blocks parallel to each other and connected to the panelsforming recesses into which the transom may slide. Bracing members 37,'33, 39 are also provided which may be located in the hull by suitablemeans (not shown) which again may be in the form of blocks connected tothe panels. Two of the bracing members 33, 39 form the back members ofseats 41. A windscreen i3 and floor boards id may also be provided.

The rear transom for a fixed open or non-ilolding boat is a single panelfiat across or curved and cut to the shape desired to joint the bottomand side panels.

If a folding transom is desired to make the entire boat fold, thetransom is cut into four pieces, one out along the vertical centre lineand two cuts along two straight lines (shown chain dotted at 45, FlGURE4) starting from the bottom corners where the side panels join thebottom panels and converging towards the vertical centre line, the angleformed by each cut and the side panel being equal to the angle betweenthe cut and the bottom panel.

Such a transom board will fold fiat either inwardly or outwardly.Outward folding is preferred as there are only two panel thicknesses atthe corners and the watertight hinge construction is greatlyfacilitated.

If a canoe shaped craft is required the panels are carried on from foreto aft without a transom at the centre.

The hull shape may vary from a fine bow entry curve to a fiat aft oreven a slightly concave shape in order to give the bottom panels a stepeffect from amidships aft.

The chine line starts at the top of the bow and carries on to the bottomof the stern transom in practically a straight line when viewed from theside. That is with the bull in the unfolded open condition the upperconvex edges of the underneath panels and the lower convex edges of theupper panels are each curved approximately helically and all lie in acommon plane.

Due to the curvature of the connected edges of the upper and lowerpanels, the opened hull cannot collapse under transverse pressure sincealthough the connected convex edges of the upper and lower panels allowfolding of the upper panels flat within the lower panels, they resistopening out of the upper panels from the lower ones because this tendsto bring the connected edges of the upper panels out of register withthe convex edges of the lower panels.

The panels are made of an elastically flexible material, for examplewaterproof plywood fiberglass sheet metal or synthetic plastics such aspolyvinylchloride.

The present invention provides a boat which can be folded in a verysimple and convenient manner thus affording ease of storage andtransportation.

I claim:

1. A folding boat hull having a deck at the forepart and havingsubstantially vertical sides abaft, comprising a first pair of flexiblebottom forming panels having contours identical to each other when thehull is folded and each having an upper edge, a flexible hingeconnccting said panels together along a continuous line including a heelportion and a bow portion at adjacent identical lower edges, and asecond pair of panels which in the folded condition of the boat are flatflexible sheets, said second panels being flat when the hull iscollapsed but being flexed when the hull is opened to form the deck atthe forepart of the boat and to form the vertical sides of the boat,said second panels having edges connected to said first panels alongsaid upper edges of the latter to which they are identical in contour,said second panels when the boat is folded, lying between the firstpanels and within the area of the first panels over the length of thelatter, a second flexible hinge connecting said second panels togetheralong the longitudinal centre line of the hull, the forepart of thesecond panels being curved upwardly above the first panels in the openposition, and said second panels being adapted to be sprung in betweenthe first panels to collapse the boat.

2. A folding boat hull as claimed in claim 1, wherein the second pair ofpanels lie substantially parallel to and between the panels of the firstpair when the boat is in a folded flat condition, and upstanding fromsaid first pair when in the unfolded open condition.

3. A folding boat hull as claimed in claim 1, wherein the keel portionof each first panel is straight and is continuous with the bow and isupwardly curved, and each first panel is provided with further edgeswhich are convex and extend over the length of the panel.

4. A folding boat hull as claimed in claim 1, wherein each panel of saidsecond pair in the folded condition of the boat has a contour comprisingone edge which is convex and extends over the length of the panel, andanother concave edge extending from the wide part of the hull along tothe position where the second panels are joined to each other.

5. A folding boat hull as claimed in claim 4, wherein with the hull inthe open unfolded condition the upper edges of the first panels and theconvex edges of the second panels connected to said upper edges all liein a common plane.

6. A folding boat hull as claimed in claim 4 wherein said adjacentidentical edges of the second pair of panels which are connectedtogether extend upwardly and longitudinally to a position where thewidth of the hull is from 70 to 100 percent of the maximum width of thehull.

7. A hull as claimed in claim 1 wherein the after end of the hull isprovided with a transom which is connected to the horizontal ends of thefirst pair of panels and to the vertical ends of the second pair ofpanels.

8. A hull as claimed in claim 1, wherein U-shaped bracing members arespaced along the inside of the hull.

9. A hull as claimed in claim 1 wherein the hinge members aresubstantially U-shaped in cross-section, each limb thereof beingrecessed to receive a panel, said members being fabricated extrudedrubber or synthetic plastic material.

References Cited in the file of this patent UNITED STATES PATENTS2,353,013 Clark July 4, 1944 FOREIGN PATENTS 529.700 Great Britain Nov.26, 194i)

1. A FOLDING BOAT HULL HAVING A DECK AT THE FOREPART AND HAVINGSUBSTANTIALLY VERTICAL SIDES ABAFT, COMPRISING A FIRST PAIR OF FLEXIBLEBOTTOM FORMING PANELS HAVING CONTOURS IDENTICAL TO EACH OTHER WHEN THEHULL IS FOLDED AND EACH HAVING AN UPPER EDGE, A FLEXIBLE HINGECONNECTING SAID PANELS TOGETHER ALONG A CONTINUOUS LINE INCLUDING A KEELPORTION AND A BOW PORTION AT ADJACENT IDENTICAL LOWER EDGES, AND ASECOND PAIR OF PANELS WHICH IN THE FOLDED CONDITION OF THE BOAT ARE FLATFLEXIBLE SHEETS, SAID SECOND PANELS BEING FLAT WHEN THE HULL ISCOLLAPSED BUT BEING FLEXED WHEN THE HULL IS OPENED TO FORM THE DECK ATTHE FOREPART OF THE BOAT AND TO FORM THE VERTICAL SIDES OF THE BOAT,SAID SECOND PANELS HAVING EDGES CONNECTED TO SAID FIRST PANELS ALONGSAID UPPER EDGES OF THE LATTER TO WHICH THEY ARE IDENTICAL IN CONTOUR,SAID SECOND PANELS WHEN THE BOAT IS FOLDED, LYING BETWEEN THE FIRSTPANELS AND WITHIN THE AREA OF THE FIRST PANELS OVER THE LENGTH OF THELATTER, A SECOND FLEXIBLE HINGE CONNECTING SAID SECOND PANELS TOGETHERALONG THE LONGITUDINAL CENTRE LINE OF THE HULL, THE FOREPART OF THESECOND PANELS BEING CURVED UPWARDLY ABOVE THE FIRST PANELS IN THE OPENPOSITION, AND SAID SECOND PANELS BEING ADAPTED TO BE SPRUNG IN BETWEENTHE FIRST PANELS TO COLLAPSE THE BOAT.